Process capability indices such as Cp, Cpk, Cpu and Cpl are common metrics to evaluate and predict the performance of a process. Although higher process capability indices indicate higher process “quality”, but a high quality process does not necessarily guarantee the fewer rates of rejects. Therefore, a process capability index based on rate of rejects or real losses is more reliable and prope...

During the past three decades, PCIs – process capability indices – have inspired hundreds of pages of scientific research. The trade-off between simplicity and precision in reproducing an overall process quality prediction is both the reason behind the criticism for Cp and Cpk and the motive for their widespread use. Indeed, their strength in simplifying the assessment of a process control stat...

Processcapabilityindicesareusedtoevaluatetheperformanceofthemanufacturingprocess.When thespecificationlimitsandthetargetvaluearenotprecise,theauthorscannotusethetraditional methodstoassessthecapabilityoftheprocess.Fortheprocesseswithasymmetrictoleranceintervals, somefuzzyprocesscapabilityindiceshavebeenintroducedsuchas  Cpk '' and  Cpmk...

The production of a process is expected to meet customer demands, specifications or engineering tolerances. The ability of a process to meet these expectations is expresed as a single number using a process capability index. When the quality of the products relates to more than one characteristic, multivariate process capability indices are applied. As it is known, in some circumstances we are ...

This paper deals with construction of confidence intervals for process capability index using bootstrap method (proposed by Chen and Pearn in Qual Reliab Eng Int 13(6):355–360, 1997) by applying simulation technique. It is assumed that the quality characteristic follows type-II generalized log-logistic distribution introduced by Rosaiah et al. in Int J Agric Stat Sci 4(2):283–292, (2008). Discu...

The manufacturing operations often involve multistage processes where the process capability of each stage is affected by the process capability of its precedent processes. This property is known as the cascade property. The purpose of this paper is to estimate the process capability of the second stage of two-stage process while the cascade property impact is removed using residuals analysis. ...